P3's really good in my opinion. It can get slow at points, just because of the nature of the game. If you wanna get the most out of the social aspect of it, you can't go to Tartarus (the tower maze where the enemies are) very often. If you're not interested in the social aspect, then playing the tower over and over can seem to drag on after a while. But still, it's a good balance and has a good story. I personally prefer to battle more, but I'm trying to max out all of my social links, so I've have to keep myself from going to Tartarus more than twice in one game month. xD
I've never played any of the other games in the Persona series, but I have played other Shin Megami Tensei games. And I hope to get Persona 4 for Christmas.